The beast within
by minerchick9087
Summary: some blood and gore when Leo was attacked as a kid he learns not long after his body isn't quite the same, as time passes he makes friends with similar problems, but when secrets come out and old enemy's rise will Leo be able to save the city 4 friendly oc, 4 enemy oc
1. Chapter 1

A/N-ok so since this is the first chapter there's going to be a lot of switching between perspectives just so you know what's going on hopefully in later chapters this will calm down also im trying to get all the description out of the way so I can get on with the action, hope you enjoy.

_Leos POV_

I could feel the blood pumping through my veins, the loud thump of my heart in my ears then the smell of meat hit me and I was off as fast of my paws would carry me, some clarification, I'm a werewolf and right now I'm hunting down my next meal, I still remember how this all started, on that horrible night.

_Flashback_

I was running through the sewers as fast as possible, tears in my eyes, Raph had just punched me real hard, I could hear them calling my name, this was the worst mutation day ever, and there had been ten of them. I knew running through the sewer was pointless they would find me, so I headed up top and realised instantly I was in a bad part of town but I didn't mind right now I needed time alone. I had my feet dangling off the edge of the building, I jumped when I suddenly heard a clatter behind me, I could have sworn I saw something move, at this point I decided to go home before I got hurt even more, but that's when a large black shadow landed in front of me causing me to stumble backwards, the thing crept forward into the moon light revelling a giant wolf about four times his size in height alone it had a large scar down its left eye and lots of its fur was mattered and bloody his eyes where dull and colourless, all the time the thing was growling at me showing its horrid teeth "s-stay away" I managed only making the thing growl louder, advancing towards me, hunger in its eyes, it opened its mouth about to take of my head, "Leonardo" I heard my father calling and so did this beast, closing its mouth and looking around and instead leaving me with a huge gash on my arm causing me to scream in pain as blood leaked from the three huge cuts when I opened my eyes the beast was gone and my father had appeared on the roof "my son what has happened" he looked worried, but I knew he wouldn't believe me if I told him the truth, "I-I caught m-my arm on some p-p-pipes" I whimpered tears rushing down my face, the cuts where stinging like hell it was unbearable all I remember after that is passing out on the way home

_Leos POV_

I look down at the limp body on the floor, his neck a bloody mess and his stomach around my mouth, delicious, my white paws and mouth where now a crimson red the blood that remained was draining to the sewers that's when my bones started to hurt and I knew it was time to get home. I ran down a few blocks and when I reached the manhole cover I was me again, blue bandana and all but my face and hands where covered in blood id have to was it off on the way, I grabbed my cell, 12:33, huh he changed early today, I quickly jumped into the sewers before the police came and ran home washing my hands along the way then went to bed before practice

_Memory_

I was sitting alone, my brothers had gone to bed and sensei was in the dojo meditating my arm was still stinging from a few nights ago but was getting better, that's when it happened my bones started aching but it soon became painful like they were snapping again and again, I bit back my scream, I didn't want to be back in medical care, my eyes started getting blurry from tears the inside of my mouth was beading because my teeth had gotten extremely sharp, my hands started to merge into what looked like a paw before I knew it I had sharp claws two furry ears my tail had grown and was bushy my nose was growing out and suddenly I could smell a lot better, not exactly a good thing in the sewers The lair suddenly started getting brighter I could actually see the other side of the room, before I knew it I had grown about four feet and was forced to walk on all fours because my hind legs couldn't support my weight, what was happening to me, I ran to find some water and when i saw my reflection, I looked like a giant wolf, my once green completion was snow white and I was covered in fur, my shell was gone and the only part of me that wasn't white was the fur around my eyes that was a light blue, the same colour as my bandana, I heard sensei exiting the dojo, I don't know how considering I was three rooms away but he couldn't see me like this, so I ran, ran far away in the sewer until eventually at 1 I changed back.

_3rd person_

Six years had gone by, since the faithful day Leo learned of his new ability not much later he met some people who had the same ability and where about his age who told him lots about what they where and what they ate, there are lots of things Leo has learned like now the only true way to satisfy hunger is to feast upon people, he can change whenever he wants but on a full moon he has no choice, he also has better senses, stuff like that and ever since he has been training, practising his transformations, the best way to kill people and keeping his senses under control.

_Leo POV_

I sighed, bored, today had been nothing special, Donnie in the lab, Mikey teasing Raph then getting beaten up by Raph but evidently broken apart by April while Casey sat laughing his ass off, nothing new yet I was also anxious tonight was a full moon and me and the guys where going hunting, I couldn't wait. The news suddenly caught my attention "..serial killer still on the loose another attack was made last night on a man who's name will not be revealed" the TV switched to the crime scene where they where interviewing the police, and I recognised the place instantly, I had to start disposing of bodies. "this guys making quite a name for himself" Raph suddenly appeared on the couch next to me "yes that is why I want you to be careful tonight my sons, and escort miss O'Neil and Mr. Jones home before your patrol" Splinter entered the room and Donnie appeared from around the corner "wed love to" he said a tad over enthusiastically, we all rolled our eyes and prepared for patrol. we had dropped April and Casey off and set out for patrol but the night was turning out to be quite unproductive not even any purple dragons, "guys can we go home, we've been out here for hours and im bored" mikey complained, again, yet I had to agree it was getting late and I was starving so we agreed to head home, "hey you guys go on a head im gonna stay out a bit longer just incase" I said, desperate to get away, my own brothers where smelling better by the second "are you sure bro, I mean with that ceria.." "ill be fine" I quickly replied cutting Raph off, that didn't make him too happy "well ok but be careful Leo" Donnie said before my brother where out of sight, I let a huge smile creep on my face as I sprinted towards the cabin. I could hear my stomach growling as the small wooden building came into sight through the thick ambush of trees, this place was just out of the city in a small woodland aria, very well hidden. As I stepped into the room warmth immediately hit me and the smell of familiar surrounded me as I walked further in I could see everyone waiting, except Roy, molly was in front of the fire, she had long golden hair with a few beads platted into it, denim blue skinny jeans, pink high tops and a pink hoodie, she had a small heart shaped locked around her neck that she never opened for some reason and she looked about 12 acted 10 yet she was 16, god only knows, next was Jackson he was stood in a corner with a drink in his hand he was only 15 but by far the tallest of all of them, he had short spiky blonde hair but it was nearly white he wore a short sleeved rock t shirt and he had sleeves of tattoos on both his arms, they where very, colourful, he also had a spiky bracelet, gray skinny jeans with countless holes in it and medium length combat boots, sitting on the sofa was Dion, she had short black hair with two long purple streaks that came down to her chest, she wore a studded black collar, a black shirt that had no buttons but crosses instead and sleeves that rested on her arm not her shoulders, on one hand she had a fish net glove and a small silver ring on the other she had a black and white stripy sleeve, she had two belts that went diagonal across her waist one white and studded the other a chain, she wore a short red skirt that had a gray under layer, she had a fishnet legging on the leg opposite her hand and wore black calf length, high-tops, she was like an emo who didn't hate everything. I had went over and sat down waiting for the final member of my group to arrive, yea you heard, my group, they elected me leader after I saved us from a sticky situation with the police, after about five long minutes Roy finally arrived, he had medium length light brown hair, he wore a beige, green jacket with a fluffy hood, lots of dog tags and chains, a yellow polo shirt with a happy sun on it, blue grey combat pants and converse shoes he was only 14 and had very high spirits, like Mikey, "look who finally showed up" Jackson said, obviously not amused with having to wait so long for dinner "I know im sorry" Roy replied bowing his head in shame I simply smiled and got up "well lets go im starving" and with that we all left the cabin in search of a suitable meal. After a good hour of searching we found some purple dragons hanging in an alleyway drunk out of their minds, "ohhh, dinner and a drink, I love it" molly's eyes lit up at the sight of food, Dion nodded in agreement, they looked at me for permission, I nodded and they got into positions around the ally ready to pounce, we transformed into our wolf forms, they waited for my mark, licking my lips I pounce on the one closest to the bin pinning him to the ground, the others jumped from there spots and a chorus of screams could be heard, I quickly sunk my teeth into his neck, blood flying everywhere, silencing him, I rip out his throat downing it in one then move onto other parts of his body ripping out his stomach and tearing the flesh from his arms, he was truly delicious, and by the delighted sounds from everyone else they enjoyed it too so they headed back to the forest. They lay outside the cabin letting their dinners settle I looked around briefly molly, the golden brown wolf with a white snout, chest, underbelly and paws lay peacefully sleeping, Dion, the jet black wolf with a studded collar and a grey snout, faded purple ears and red streaks on her back that made her look like tiger, she sat licking the blood from her paws, Jackson was a yellowish white his hind paws and ears where dark brown and his two front paws had wired swirls and symbols etched into the fur he just lay looking grumpy as always finally Roy, the entire top half of his body was a dark grey whilst the bottom half like under his chin, tail, stomach and paws where white, he was just yawning, the only thing all five of us had in common was that we all have numerous scars all over our body from fights with other animals, I felt my eyes start to shut and decided to head home *im going home* I barked, the others nodded and I left, as I was exiting the forest I heard a series of howls and by instinct howled back causing many house pets to go crazy, I took it as my queue to go.

_raph POV_

We had left Leo to do some extra patrolling and came home, we had some pizza watched a few movies but now my bros where passed out and Leo still wasn't back, I check the clock 11 at night, I start worrying what if he's hurt, what if he ran into that killer my mind starts rasing with all the things that could have happened when suddenly I hear something down the tunnel, the Leo appears "Leo, oh my god, where the shell have you been" he says nothing but I see guilt in his eyes and blood on his face, wait what "is that blood" I ask pointing to his chin, he seemed abet taken back "what this no, no its, sauce I got a bite to eat before I came back" he smiled shyly rubbing the red substance from his chin "oh, ok well listen im going to bed see ya in the morning" I say before climbing the stairs to my room. I plonk myself on the bed "sauce my ass" I couldn't believe Leo would lie to me but now I was curious but being the caring person I am and considering Leo would try to lie to me of all people to keep this secret ill keep everyone else out of it, this is my investigation.

**ok guys that chap 1, tell me what you think, should I keep talking in first person or am I better in third. thanks ;)**


	2. Chapter 2

_Leo POV_

I awoke hungry, I mustn't have eaten enough last night, I would have to slip out and get something later, I got out of bed, every bone in my bony ached, I heard a knock at my door "come in" I mumble as a very happy, freckled face appeared in the door "hey bro breakfast is ready" Mikey sing songed "ok I'll be down in a minute" I reply, and with that he left to go down stairs. I walked into the bathroom, and looked in the mirror and realised I had a small cut on my shoulder nothing big, it must have been off last night, I gave it a clean and went to get breakfast

_Mikey POV_

I went to get Leo for breakfast, I had made my world famous pancakes, I knocked on his door "come in" he said, if I wasn't listening I wouldn't have heard it, when I went in the room was very dark he didn't even have a lamp on and when I looked he had a small cut on his shoulder, probably off last night when he insisted on staying out longer. I told him breakfast was ready and left, when I got back down stairs Donnie and Raph had always started digging into the pancakes, Donnie was fiddling with some sort of gadget and Raph looked deep in thought which was strange because that was usually Dons thing, "whatcha thinkin bout" I asked snapping him out of his trance "uh, nothing Mikey, jus lovin these pancakes" he said shoving a forkful of syrup covered pancakes into his mouth, I just raised my eyebrow, Raph was acting very happy, I shrugged it off and got my own pancakes before Leo came down stretching and clicking his bones, I could hear it from my seat which made me cringe, he grabbed a plate and started eating.

_Leo POV_

I was eating Mikey's pancakes but they were tasteless and not filling in the slightest, i needed meat, now i felt like I was starving, and I could smell my brothers from where I was suddenly Donnie was looking quite appetising, "hey im going to go out for a run" I said quickly dashing out of the lair "dude wait, you didn't finish your pancakes" I heard Mikey calling as I ran through the tunnels towards the surface. I had been jumping across the rooftops as I looked for some food, I was trying to find some purple dragons or foot soldiers, but I was having no luck, I glance down to see an old homeless man, he was quite pudgy too, no I couldn't this man was innocent he hadn't done anything wrong, but right then my stomach reminded me I needed something to eat, it was just one guy no one would miss him, with that I transformed not making a sound laying my paws gently on the roof, my tail swished back and forth and my eyes narrowed and in a flash I jumped down on top of him going through my usual routine tear out the throat then feast, my nose picked up another sent, I followed it until i found myself staring at the roof where three turtles stood dumbfounded, oh no, I didn't want to attack my brothers but instincts where kicking in and I could feel myself moving towards my 'prey' and I couldn't change back or else they would find out my secret, I tried to run but the beast inside wasn't about to wasn't good food and before I knew it I was on the roof staring down my own family *run, get away* I tried to warn them but it came out as angry growls and barks "bring it on ya beast" Raph challenged, shielding mikey and don "technically its just a big wolf" Donnie corrected "technically I don't care" raph shot back, turning to face me again, I knew I couldn't fight them, if so much as scraped them they would be cursed unless I killed them, and I didn't want them to go through what I did, the pain, yet to my dismay I started advancing on them and they didn't back off in fact at that point mikey had jumped in the air "booyakasha" he screamed, survival instincts kicked in and I went to attack, but before I could I found myself on my side and Roy standing over me, thank god *come on we should get out of here* he barked *I want to but they smell too good* I growled back, he thought for a minute *try not to kill em and ill be right back* he dashed off and I got worried, my brothers where flat against the wall, I look at them causing raph to give me a glare that said 'don't you dare'. it took every ounce of self control I have not to mall them to pieces, when suddenly I smelt something tasty, knowing full well this was my best opportunity I dashed off following my nose until I came face to face with Roy covered in blood and what smelt like deer guts. I changed back into my normal form Roy following my lead "thanks for the save" I said happy to be away from any danger "no problem, I was passing through and thought you could use a hand" he replied scratching the back of his head, I laughed as he failed to get the blood off "come on lets get to the cabin and get you cleaned up" I snickered, we ran off out of the city, and the cabin couldn't have appeared sooner the deer guts where starting to smell real bad.

_Donnie POV_

Leo had left in a hurry, all I know was that raph immediately tried to follow him "and where are you going" I ask sceptically as he froze mid dash "nowhere" came the slow reply, I gave him my best death glare and he cracked like an egg "I've just been worried about Leo lately that's all, just going to make sure he's ok, you can come if you want" he finally added so we set off in search of our brother. Fifty rooftops and thirty alleyways later and still no sign of Leo, and we had been our for a good part of the morning just then I saw something out the corner of my eye, I turned to see something I wish I never saw on the roof just across the road from us there was a huge white wolf about seven foot tall with what I thought to be blue on its eye, I noticed my brothers had seen it too as they where staring in the direction of the thing, just then the beast leapt from the building onto an old man, ripping him to shreds, coating the nice white fur in red. me and my brothers where in shock, once the thing had finally skinned the poor man it started sniffing until it made eye contact, just staring for a few seconds before dashing across the road and climbing the building and coming face to face with us, normally I wouldn't be so scared but this thing literally had skin in its teeth, the large wolf started growling and barking, "bring it on ya beast" he snarled sais at the ready, the nerd in me couldn't resist "technically its just a big wolf" I corrected him, "technically, I don't care" came his witty reply, then the wolf started walking forward showing a full set of teeth, very sharp teeth I might add. mikey leapt in the air "booyakasha" he yelled his catch phrase, the beast looked like it was about to swallow him whole when suddenly another one came out of nowhere, knocking the white one to the ground, we took the opportunity to back off a bit, what I wouldn't kill to study these creatures they seemed so intelligent right now they seemed to be having a conversation, barking at each other, the second one who was half grey, eventually left leaving us alone with the one currently trying to tear our heads off, I had told my brothers before not to attack it unless it attacks us, and for some reason it just stood there having a staring contest with raph it seemed like hours before the wolfs head snapped to the right and it dashed off, "are we gonna go after it" mikey asked hopefully "no mikey, and even if we wanted to that thing is way to quick" raph said quiet deflated, I get the feeling he wanted to go after it to, "if we could learn a bit more about it we might be able to find some answers like what that was and where it came from" we nodded in agreement, and headed home, mikey almost bursting with excitement to tell everyone what happened, then raph nudged me and whispered "hey, do ya think that things what's been Killen people", I pondered for a second "I, I don't know raph, but there's a good chance it may be" I offered I didn't really know what to tell him, id have to do some research "hey guys, what about Leo", my eyes suddenly widen as I realise we got all the way into the sewers before we realised we had completely forgotten about Leo, "im sure he's fine, after all he only went for a run" I said, we all shrugged it off and continued home.

_Leo POV_

"so I said meal? you are the meal" the whole cabin erupted with laughter Mollie always had some of the best jokes, they even got Jackson laughing and that's saying something, I quickly checked my phone and gasped at the time "crap, 11:30 already, guys I gotta go but ill see you tonight right" a said grabbing my katanas "of course you will silly" Dion replied taking another shot nodding, I left hearing a bunch of "see ya's" and "bye's" as I sprinted to get home. I was just about to lift up the man hole cover when I heard "oh, hey Leo" I glanced up to see April and Casey walking over to me "what you doin out this early blue" I hated that stupid nickname, we all had had one Donnie was 'Don' mikey was 'freckles' raph had the glory of being called raph, lucky, and poor April was 'red' I personally found it offensive to gingers, but if she didn't mind, I didn't "oh I was just out for a run" I said not making eye contact and lifting the cover to the sewers, the smell hit me like a brick and I tried hard not to gag, I signalled to the two in front to go first, and as they climbed down I took one last breath of fresh air before heading down myself. the second when entered the lair we were bombarded with mikey who quickly shoved us on to the couch where master splinter sat, I looked at him questioningly, all I received was a shrug, mikey called raph and Donnie who appeared in seconds, "ok, ok so your never going to believe what happened" mikey started "we where attacked by a giant wolf" Donnie took over "a giant wolf" Casey suddenly looked interested "yea, this thing was like seven foot tall" raph tried to reach the height he was describing with his hand but Leo knew better than anyone just how tall this 'beast' was "no way" April gasped "yea way, this thing was sowing its teeth and growling at us all angry" I almost laughed at mikey warping his face to imitate mine "my sons how did you encounter such a beast" splinter asked "well we went looking for Leo because he left in quite a hurry, after a while we saw this huge wolf over the street pounce down on this homeless guy and just started ripping him apart then it saw us.." Donnie stopped for a second "I think it could have killed us if the other one hadn't came along" he ended simply "there where more" April and Casey said in unison, my brothers nodded "so now we have to face wolfs krang and shredder" I asked acting surprised so I didn't seem suspicious "it would appear so, Donatello do you know anything about this creature" splinter questioned standing up "not really but im analysing some DNA from its fur that it left, ill have a result in a few hours" my heart stopped, DNA, my DNA was in Donnie's lab in fur form, sure he would find out my breed and some of the places I go but he would also learn that it was my DNA, I had to get that sample but how "hello, Leo bro, anyone home" I snapped out of my trance to see mikeys hand in my face "uh yea sorry just day dreaming" I nodded as he walked to the kitchen, I quickly glance around Donnie's lab door is shut which means he's in there, crap, this would be difficult.

one hour later

I walked into Donnie's lab quietly and saw him crouched over a desk writing something and occasionally looking through a microscope, "hey don, how's it going" I ask as casually as possible even though im going insane on the inside "hm good I guess though this molecular structure is made up of some complex covalent bonds and it has four biopolymer strands, four" I had no clue what he just said and apparently neither did my face "most people have two biopolymer strands that hold information and code that tells you who and what you are, this one has four making more links and more genetic coding, all I know is that it's a rare breed of wolf called a Miha, but there usually in colder places and not nearly as big as the one we saw" he simplified, hooray after all these years I've learned what breed I am, now I can forget all my problems and live happy "Leo I don't want to sound rude but could you go, I kind of want to get this done" great now I was getting kicked out the lab "sure Donnie see you around" I waved before closing the door, I sighed, now how was I supposed to get that sample, as I see it there are two options, 1. barge in there like its world war three and raise suspicion, probably more trouble than its worth or 2. run away for the night and delay the inevitable, by the looks both would lead to his secret coming out, so he chose between the two and took the rout that any sensible person would, he ran like a madman out of the lair and to the only place he knew he could run, the cabin.

_Raph POV_

I was a bit annoyed that I had to let my bros in on the little investigation I was looking into but that didn't matter now, sauce or no sauce this wolf is way more important than what Leo had on his chin last night, it had been a few hours and Leo had left a while ago, we where all awaiting Donnie to tell us what he knew. About an hour later the two lab doors flew open to revel a very shocked Donnie "Donnie did you find out anything useful" April asked looking over the edge of the couch, Donnie walked to the canter on the room, blocking the TV unfortunately so I turned it off "um well ok, I did find out a few things" he said nervously scratching his head " "well spit it out don" Casey urged "ok, ok the wolf we saw was a rare breed called a Miha from what I gathered and alpha, it had huge traces of wood and foliage suggesting it lives in the woods" Donnie started getting nervous "well what are we waiting for lets go" mikey jumped up and down on the couch "well you see there's one more thing, what I was examine the fur I found that every 50 nanometres there was some, uh Leo DNA" everyone just looked confused "wait wait wait, Donnie what are ya sayin" I ask slowly standing up fearing I already knew the answer, "that wolf we saw, it was Leo"

_Leo POV_

I was running in wolf form towards the cabin, pondering how long I should hide there or if I should just run away forever, when I heard something just over the rooftops I try to focus my hearing but before I know it im surrounded by foot, razar and Karai "what on earth are you" she asked placing her hand on her hip I just growled back "oh not the talkative type are we, fine by me, foot ATTACK" she screamed pointing at me this would be fun there was only about 20 of them so I started ripping off heads, pulling out guts and such by the time I was done the roof looked like a dead pool party with razar and Karai staring in bewilderment ill admit I did get a small scrape on my leg from some ass who snuck up on me I turned to Karai and growled, she moved out of the way and I continued to the cabin. when I got there four happy faces greeted me, well three and Jackson "what are you doing here so early Mr. unpredictable" Dion asked moving along on the couch so I could sit down "my brothers, I think they found out" Roy and Mollie gasped "oh dear" the Irish man piped up "so what are ya gonna do" Jackson asked, I was quite surprised to see he cared "I, I don't know" its very rare that I don't have a plan but when I don't its because there's no safe way to get through something without someone getting hurt, and right now that someone was me. right then everyone piped up, myself included, this because there was a smell in the air, human, and that meant some unfortunate was on out territory, "go out back, turn, and well take this loser out together" I wisper. We seek out the back door and all transform *Mollie, Roy you two go left, Dion Jackson you two go right, ill take the long route well box them in and take them out* I barked quietly then we all dispersed heading our separate ways, this should be fun.

_April POV_

We where walking through the wood that where on the outskirts of the city looking for Leo and having no luck whatsoever "hey guys, what's that" mikey asked pointing to a huge ditch "its nothing but it looks nice" I said walking to the edge and looking down, to my surprise there was actually a big staircase leading down you could fit three people on one stair they where huge, at the bottom there was a small pond, a few evergreens and one huge weeping willow tree that towered over a small cabin "hey look here" I called, and they all came rushing over "wow" was all Donnie could managed "well lets go" raph said already heading sown the stairs with Casey so we followed. we eventually got to the bottom, this thing had to be about forty feet deep, we started waking towards the cabin when I could have sworn the shadows moved "uh guys I think theirs something else here" Casey whined guess he saw it too " don't be redicu…" mikey turned to us and slowly faded out and stood still, eyes wide, we all turn around to find two huge wolfs in our face, both about 6 foot "that's one of the ones from before" raph pointed to the half grey one who seemed baffled, if that's possible, it let out a series of barks and growls before two more emerge from the shadows one the same height as the others and another that had to be at least 8 foot, it had weird patterns on its front paws for some reason and then one more coming from the only exit we had we where encircled by wolfs "so which ones Leo" I ask quietly and raph pointed to the white one with blue markings around its eyes, the five wolfs just stood there before growling and walking off "hey now wait a minute, where do you think your going" Donnie shouted after them, but they only growled over there shoulder "aw come on blue, don't you think we deserve an explanation" Casey pleaded witch was strange to say the least, one of the wolfs barked lowly and eventually they all turned into the people they where supposed to be, Leo sighed "let me start from the beginning."


End file.
